Preterm infants with birth weight less than 1250g will be studied to determine whether treatment with recombinant human erythropoietin (EPO), beginning in the first 4 days of life and continuing through discharge or 35 weeks post conceptional age, can: reduce the number of transfusion- related donor exposures and the number of transfusions; and increase the number of non-transfused infants that occur when dedicated units of red blood cells and transfusion guidelines are used in comparison to infants who are not treated with EPO. (This is a NICHD Neonatal Research Network Trial.)